Hydraulic engine-starting device



March 28, 1961 M. J. DUER ET AL 2,976,863

HYDRAULIC ENGINE-STARTING DEVICE Original Filed Nov. 7. 1955 3 Sheets-Sheet 1 IN V EN TORS I l I March 28, 1961 M. J. DUER ET AL 2,976,863

HYDRAULIC ENGINE-STARTING DEVICE Original Filed Nov. 7. 1955 3 Sheets-Sheet 2 IN V EN TORS March 28, 1961 M. J. DUER ET AL HYDRAULIC ENGINE-STARTING DEVICE 3 Sheets-Sheet 3 Original Filed Nov. 7. 1955 l v nt 7/701: J 32127, l/yaed 7%112/6/1 United States Patent HYDRAULIC ENGINE-STARTIN G DEVICE Morris J. Duer, Dayton, Ohio, and Clyde W. Truxell,

Franklin, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Continuation of abandoned application Ser. No. 545,186, Nov. 7, 1955. This application Dec. 1, 1958, Ser. No.

16 Claims. Cl. 123-179 such a fluid motor and a starting drive mechanism.

This is a continuation of our copending application Serial No. 545,186, filed November 7, 1955, now abancloned.

Hydraulic motors of the aforementioned type include a rotating cylinder barrel having a plurality of cylinder bores formed therein. A piston is reciprocably mounted in each of the. cylinder bores and these pistons bear at one end against a cam as rotation of the cylinder barrel relative to a valve member having fluid inlet and exhaust ports controls the sequential admission and discharge of pressurized hydraulic fluid to and from the several cylinder bores. The cooperative action of the fluid pressure and of the cam acting on the several pistons causes the reciprocation of the pistons within the cylinder and this reciprocation. is translated by means of the cam into rotation of the cylinder barrel. Such motors may be used with fluid over a wide range of fluid pressures and are capable of delivering high torques at relatively high rotational speeds.

The invention has particular application to hydraulic motors of the rotating cylinder type in which the cylinder barrel rotates in thrust engagement with a valve plate member; the cylinder bores being formed axially of the rotating cylinder barrel; the pistons mounted therein bearing against a cam plate inclined to the rotational axis of the cylinder barrel; and the cam plate ordinarily being in the form of an antifriction bearing. In such motors, lateral force components occurring between the ends of the several pistons and the inclined cam plate tend to cock the pistons within the cylinder barrel with resultant deflection of the motor drive shaft and cocking the cylinder barrel with respect to the valve plate. The deflection of the drive shaft results in the application of wear-increasing loads to the shaft-supporting bearings and the cocking of the cylinder barrel with respect to the valve plate results in the leakage of pressurized hydraulic fluid between the valve plate and the valve end of the cylinder barrel thereby reducing the available torque, the maximum speed, and the acceleration response of the motor. Such leakage also reduces the effective period of operation that the motor can be utilized for a given amount of pressurized fluid. In addition to the performance-reducing leakage resulting from cocking or" the cylinder barrel relative to the valve plate, such cocking results in substantial increases in the frictional loadings occuning between the several elements due to the breaking down of the protectivelubricating films therebetween. These increased frictional loadings, in addition to reducing the efiiciency of the motor, result in excessive and uneven wear between the several elements which in time results in still further performance-reducing leakage.

It should be noted that the aforementioned lateral forces and the detrimental effects resulting therefrom are 2,976,863 Patented Mar. 28, 1961 necessarily of greater magnitude during the starting phase of motor operation than when the motor is operating at running torque and speed due to the relative torques involved. In hydraulic engine starter systems where the supply of pressurized fluid is generally limited to that contained in a charged pressure accumulator or reservoir, the starter motor is normally energized for only relatively short periods of time. Consequently, in the application of a hydraulic motor of the aforementioned type in an engine-starting mechanism, it is extremely desirable that the performance-reducing leakage, frictional loads, and wear occurring between the cylinder barrel and the valve plate be held to a minimum as engine-starting characteristies are generally dependent upon the torque, speed, and the acceleration response of the starter motor.

Among the several objects of the invention is to provide an improved hydraulic fluid motor of the aforementioned type in which cocking of the cylinder barrel with respect to the drive shaft and the valve plate is prevented thereby reducing leakage, frictional loadings, and wear between the several elements and permitting a maximum conversion of hydraulic energy to mechanical energy; which is of simple design and relatively economical to manufacture; which is physically interchangeable with electrical starter motors in existing engine-starting installations; and which is adapted to produce substantially higher values of torque, acceleration, and speed than provided by existing electrical and hydraulic starter motors of comparable size.

In the main, the foregoing objects are accomplished in accordance with the invention by providing a hydraulic starter drive device including a hydraulic motor having a cylinder barrel rotatably journaled adjacent its ends in a tubular housing portion so as to prevent cocking of the cylinder barrel relative to its valve plate, an overrunning clutch starter drive mechanism adapted to be driven by the hydraulic motor, and a combined motor control valve and starter drive actuating lever mechanism; the lever mechanism being arranged to first engage a starter pinion gear with an engine ring gear and subsequently, in the same movement, opening the motor control valve to admit pressurized fluid to the motor when the starter gear is in mesh with the engine ring gear.

The combined means for accomplishing the foreoing and other objects, advantages and features of the invention will become apparent from the following detailed description of a preferred embodiment thereof in which reference is made to the attached drawings, in which:

Figure l is an elevational view of a hydraulic enginestarting device embodying the invention; 7

Figure 2 is a sectional view taken substantially on the line 22 of Figure 1 with certain additional portions thereof broken away and in section;

Figure 3 is a sectional view taken substantially on the line 33 of Figure 1;

Figure 4 is a sectional view taken substantially on the line 4-4 of Figure 2;

Figure 4a is a perspective view of a preferred form of the starter drive mechanism; and

Figure 5 is .a sectional view taken substantially on the line 5-5 of Figure 1.

Referring more particularly to the drawings, Figures 1, 4, and 5 show a hydraulic engine-starting device comprising a casing 10,,a rotating cylinder motor 8 and an overrunning clutch starter drive mechanism 6. The casing 10 includes a cap member 12, a tubular housing member 14, a valve or porting plate 16, a motor-mounting adapter 18, and an engine-mounting starter drive casing 20. The cap member 12, the housing member 14, and theporting plate 16 are sealed relative to each other by suitable gaskets such as shown at 13 and 15 andform a housing chamber 2 2 forthe hydraulic 'motor 8. The 1 porting plate 516, the adapter member 18, and the enginemounting casing 20 similarly form a housing chamber 24 for the starter drive mechanism 6. The various components of the casing may be assembled by any "suitable means but are bolted together in the preferred embodiment as described in greater detail below to provide sufficient adjustability of mounting to adapt the starter mechanism to various engines and for replacement of electric motors in existing engine-starting installations.

The starter motor 8 includes a drive shaft 26 which is journaled in the porting plate 16, as indicated at 28, and in the starter drive casing 20, as indicated at 30. The shaft projects Within the motor housing chamber 22 and is connected by straight splines 32 to a cylinder barrel or block 34. A spring 36 interposed between the cylinder block and a snap ring 38 mounted adjacent the end of the shaft tends to bias the block 34 into fiuid pressure sealing contact with mating surfaces of the valve plate 16. The biasing action of the spring 36 acting on the shaft also maintains a thrust collar 40 carried by the shaft 26 intermediate its ends in rotative thrust engagement with a shoulder formed by counterboring the valve plate 16, as indicated at 42. The cylinder barrel 34 is rotatively supported adjacent the axial ends thereof by axially spaced needle bearing assemblies 44 and 46 mounted within the housing member 14.

g The cylinder barrel 34 has a plurality of cylinder bores 48 formed therein which extend axially of the cylinder barrel from its end opposite the valve plate 16. The axes of these bores are parallel to the common rotative axis of the shaft 26 and the cylinder barrel 34 and are equally spaced therefrom. Each cylinder bore terminates in a port 51} of somewhat smaller dimension opening to the end surface of the cylinder barrel 34 adjacent the valve plate. A .piston 56-is reciprocably mounted in the open-end of each of the cylinder bores. These pistons arein the form of relatively thin-walled cylinders which are closed at their ends remote from the ports 50. The closed ends of the pistons are externally rounded about a center lying on the axis of the piston at a radius slightly in excess of the diameter of the. piston. These rounded ends of the pistons normally project from their respective cylinderbores and'engagea cam'ring in the-form of an inner race 58 of an angular ball bearing assembly 60. The outer race of the bearing assembly 69 is carried by and serves to align the end cap 12 and the adjacent end portion of the'tubular housing member 14. The adjacent end-portion of the housing member is angularly-inclined to the cylinder-barrel-supporting portion thereof so that the axis of the ball bearing assembly 60 is in clined to-and intersects the axis of the shaft 26 substantially at a point lying in'a plane containing the centers of curvature of the rounded piston ends and consequentially normal to the axis of the bearing assembly.

Asthe cylinder barrel is rotatedrelative tothe valve 'platefthe ports 50 register alternately with a fluid pressure inlet port 52 and'anoutlet port 54 in the valveplate 16 thereby sequentially introducing and discharging pressurized fluidfrom their respective cylinder bores to effect the driving rotation or the cylinder barrel by the cooperative action of the pistons andthe inclined camring "as set forth in greater detail below. Both the inlet port 52 and the outlet port54 are in the form of arcuate grooves opening'on the motor chamber 22'and subtending an included angle of approximately. 150 degreessyrnmetrically of a common diametrical planeat a radius oonirnonto the ports '50'about theaxis of the shaft 26. :As'c'onventio'nal in 'rnotors of this type, the valve v.plate is providedwith'anannular groove 62 outwardly of the ports 52 and 54'andwitha'counterbore 64 coaxial with the shaft 26 to limit the surfaceareas of the valve plate and the rotary 'cylinderbar'rel in'bearing engagement. This limitstlieibias'ing effect of the leakage pressure acting 'betweemthe cylinder banerana the valve plate which tends to'counterbalarice the combinedthrust of the spring 36'audth'e'fluid Hac'kpressures on the plate.

5 with respect to the drive shaft and the valve plate.

shaft.

tween the mating valve faces.

In conventional motors of this type, as mentioned above, the reactions occurring between piston noses and the inclined cam member result in deflective loading of the drive shaft and in the cocking of the cylinder barrel Since the deflective loading of the drive shaft is dependent upon the torque loadings of the individual pistons, the resultant deflection of the drive shaft displaces the cylinder barrel transversely of the valve plate in accordance 10 with the rotative speed and loading of the motor. The

transverse displacement of the cylinder barrel results in dynamic unbalance with consequential increase in the vibrationlevel of the motor and substantial reduction in the operative life of the bearings journalling the drive Where the operative application of the motor requires generally continuously changing speed and load conditions as in hydraulic engine starter applications, the consequential continuous changing in the transverse displacement of the cylinder results in excessive wear be- Transverse displacement of the cylinder barrel relative to the valve plate may also result in a reduction in the effective areas of the port openings thereby throttling the pressurized fluid to and from the cylinder bores. Cooking of the cylinder barrel with respect to the valve plate in conventional motors of this type permits performance-reducing leakage of the pressurized fluid to occur between the mating faces of the cylinder barrel and the valve plate, and under extreme load conditions approaching locked torque may even provide a direct fluid connection between the inlet and outlet ports of the valve plate. Such cocking of the cylinder barrel also tends to cut the film of leakage fluid lubricating the mating surfaces of the cylinder-"bar- 'rel and valve plate and the resultant 'metal-to-metal contact results in excessive friction and scoring of the end "faces ofthe cylinder barrel and valve member.

Tolimit the detrimental cooking of the cylinder barrel with respect to the valve plate in such motors, it is conventional toprovide a spring to exert an axial thrust on -the cylinder barrel tending to maintain the cylinder barrel tion. Since the thrust exerted by the springrnust be of suflicient magnitude to resist leakage-inducing cocking of the cylinder barrel, the frictional losses and wear of the .mating port surfaces are substantially increased. It should be noted that if some provision were-not made for limited universal action between the cylinder barrel and the shaft, the interposed spring would be incapable of resisting the cocking tendency applied to the cylinder barrel. But the use of such spline connections permits somewhat greate rdeflection of the drive shaft and increases the detrimental results stemming therefrom as discussed aboveyresults in impacting of the spline teeth with resultant torsional vibration and fatigue problems; ,andincreases the relative wear between piston noses and elements-of the cam assembly due to the greater lateral displacement and the reduced cocking of the cylinder barrel. v

By rotatably supporting the cylinder barrel 34 within themotor-housing in accordance with this aspect of the invention as hereinbefore described, deterimental cocking 65 of the cylinder barrel and deflection of the drive shaft are prevented. This permits theuse of a straight spline connection of relatively close tolerance between the -drive shaf-t "and barrel which reduces the impacting there- -between and the torsional vibration and fatigueproblems inherent in conventional motors of this type. vSince the needle bearings prevent cocking'and-displacement of the cylinder barrel, the thrust exerted bythe spring36need be no more than sufficient tomaintain the cylinder bar- ,rel in sealing engagement with the valve plateunderall operative conditions. By properly proportioning the senses areas of the cylinder barrel to which the leakage and back pressures are applied and the biasing action of the spring, effective sealing between the cylinder barrel and the valve plate can be achieved without excessive thrust between the bearing surfaces and without excessive friction and wear which would result therefrom. It has been found from comparative tests that motors constructed in accordance with the invention are capable of developing substantially greater rotational speeds, faster rates of acceleration, higher torques, and consequentially of greater work output per unit of pressurized fluid under identical operative conditions than similar commercially available hydraulic motors of comparable size and displacement and of conventional construction.

The ends of the arcuate outlet port 54 communicate with two bores 66 and 68 extending laterally of the valve plate from opposite sides thereof. Normally, one of the bores 66 and 68 is plugged while the other bore is connected to a reservoir by suitable means; the use of the two bores being interchangeable. As shown in Figure 3, the opening of the bore 68 is sealed by a pipe plug 70 and the opening of the other bore 66 is provided with a fitting 72 which is connectable to a suitable fluid reservoir, not shown, by suitable piping, also not shown. The bore 68 is extended to intersect the counterbore 64 surrounding the shaft 26 as well as the outlet port 54 to provide for the drainage of leakage fluid from the counterbore 64.

Two passages 74 and 76 extend axially of the valve plate member and interconnect the annular groove 62 with the bores 66 and 68, respectively, to provide for draining the leakage fluid from the main portion of the motor chamber directly to the bores 66 and 68. At least some drainage of the leakage fluid in the main motor chamber may also be accomplished by the return of such leakage fluid to the.

counterbore 64 between the lands of the splining 32.

The arcuate pressure inlet port 52 of the valve plate member communicates through a radially extending passage 82 with the outlet chamber 78 of a valve 80 which is.

adapted to control the supply of pressurized fluid thereto from a suitable pressure source, not shown. As best seen in Figure 5, the control valve assembly 80 includes a valve body 84 having a cylindrical bore 86 extending therethrough. The outlet chamber 78 is in the form of an annular groove opening on the bore 86 adjacent the right end of the valve body, as shown, and a similar annular groove is spaced longitudinally of the body member 84 from the outlet chamber 78 and forms a valve inlet chamber 92 connectable through a fitting 94 to the source of pressurized fluid. The valve body is mounted on the valve plate member 16 by bolts 88, the axis of the bore 86 being disposed in parallel relation to the axis of the drive shaft 26. An O-ring 90 interposed between the valve body and the valve plate serves to seal the aligned openings of the valve outlet chamber 78 and of the passage 82.

A valve spindle 96 is reciprocably mounted in the valve bore 86 and is adapted to control the flow of fluid between the inlet chamber 92 and the outlet chamber 78. A bore 104 extends axially of the valve spindle 96 from one end thereof and is sealed by a plug 106 to form an inner chamber 105. The opposite end of the valve spindle 96 is provided with a pin-and-slot connection 100 with an arm 120 of an actuating lever assembly which is adapted to shift the starter drive mechanism to its drive position in the same movement effecting the opening of the motor control valve. The valve spindle is provided with two belts of radial ports 108 and 110 and with a single radial bleed port or orifice 111. The ports 108, 110, and 111 are spaced longitudinally of the spindle and interconnect the chamber 105 with the outer surface of the spindle. The spacing of these ports relative to the valve inlet and outlet chambers '72 and 78 is necessarily dependent upon the relative geometry and dimensions of the actuating lever assembly and of the starter drive mechanism 6. As explained in greater detail below, this spacing is such that when the spindle has been shifted by the actuating lever 6 assembly a predetermined distance to the right from its extreme position as shown in Figures '1 and 5,' the port 108, the orifice 111, and the chamber 105 interconnect the inlet and outlet chambers of the valve body thereby metering a small flow of pressurized fluid to the motor and initiating a relatively slow rotation of the motor. Upon further shifting of the valve spindle 96 to its extreme right-hand or full-opened position corresponding to a shift of the starter mechanism to its drive position, the ports 108 and and the spindle chamber 165 interconmeet the inlet and outlet chambers of the valve body to,

apply the full actuating pressure of the supplied fluid to the starter motor 8.

Three resilient O-rings 112, 114, and 116 are interposed between the valve spindle and the bore 86 to prevent-leakage therebetween from the valve inlet and outlet cham- It will be noted that when the valve is in its interpressure valves having one or more axially extending ports for interconnecting the inlet and outlet chambers in the valve body.

The actuating lever assembly includes the lever arm 120 which is formed integrally of a lever member 118.

An intermediate portion 121 of the lever member 118 is disposed laterally of the arm 120 and is pivotally mounted in a bore 122 formed in the motor-supporting adapter member 18. The axis of the bore 122 is spaced from and parallel to a plane containing the axes of the drive shaft and the valve bore 86 and the projection of the pivot axis on this plane is normal to the axes of the drive shaft and the drive bore. The end 123 of the lever member 118 remote from the arm 120 is coaxial with the intermediate pivot portion but is of a reduced diameter and projects from the bore 122 to serve as an internal guide" for a lever-biasing helical spring 124. The spring 124 is prestressed to rotate the lever arm 118 in a valve-closing direction; one end of the spring 124 being restrained by a slot 125 provided in the spring guide end of the lever member 118 and the other end being restrained by the motor-mounting adapter member 18. One end of a second lever member 127 is mounted in a bore extending diametrically of the pivot portion of the lever member 118. The lever member 127 is bifurcated at its other end to provide two lever arms 128 having laterally extending end portions 129 adapted to engage and shift the starter drive mechanism to its drive position. A handle or lever am .126 is secured to the lever arm 120 by any suitable means.

The starter drive mechanism 6 is preferably of the overrunning clutch type and includes a starter pinion gear 138 which is adapted to be selectively shifted into engagement with a flywheel ring gear 132 of an internal;

combustion engine; the ring gear 132 being shown in broken lines in Figure 5. The pinion gear 130 is internally splined as indicated at 131 to slidably engage splines 133 formed externally of a sleeve 134 which slid ably embraces the drive shaft 26. The sleeve 134 is adapted to be driven by and constitutes the driven or output member of an overrunnin-g clutch assembly indicated generally at 135. A helical compression spring 136 spacedly embracesthe sleeve 134 and is seated" at one end against the drive pinion 136. The opposite end of the spring 136 is Seated against a radially extending annular shoulder formed on a spring-seat-and-. guide member 137 slidably embracing and abutting the clutch end of the output sleeve 134. The pinion gear 130 is retained on the sleeve 134 against the biasing action of the spring 136 by a snap ring assembly 138.

The overrunning clutch 135 is preferably of a roller or.b'all..bearingtypehaving an-input sleeve 139 which is internally splined on the drive shaft 26 as indicated at 140... A collar- 144 carried by the input sleeve 139 has an outwardly opening groove therein which rotatably mounts a second collar 146. As best seen in. Figures 2 and 4,. the collar 146 is provided with an outwardly facing groove 148 subtending an angle of approximately 225 degrees, the end'sof which engage the laterally extending end portions 129 of the bifurcated lever memher 127.

As indicated above, the various components of the casing 10, in accordance with one aspect of the invention, are preferably bolted together to provide suflicient adjustability of mounting to adapt the starter mechanism to various engines and for replacement of electrical motors in existing engine-starting installations. As best seen in Figures 2, 3, and 5, four bolts 158 secure the tubular motor housing member 14, the valve plate member 16, and the motor adapter member together; the holes for the bolts 158 in the several members being disposed symmetrically of the plane of the axes of the valve bore 86 and of the drive shaft 26 at an angle of 30 degrees about the axis of the drive shaft. This symmetrical arrangement of the bolts 158 and the holes therefor permits the rotation of the tubular housing member 14 and the end cap 12 through an angle of 180 degrees relative to the valve plate 16, and to the adapter member 18 and control valve 80 secured thereto, to effect a reversal in the direction of motor rotation. This permits the same motor to be utilized for engines having either rightor left-hand crankshaft rotation with only asimple change in. the rotative direction of the overrunning clutch unit 135.

The adapter member 18 accommodates the mounting of. the motor on different engines. The engine-mountingstarter drive casing 20 is of a commercially available standard construction having a laterally extending mounting flange formed thereon adjacent its end remote from the gearing 3B. This flange is provided with three bolt holes 150 arranged equi-angularly about the rotat-ive axis of the drive shaft for the bolts mounting the starter unit on the engine. The flange of the drivecasing 20 is also provided with four equi'angularly arranged-bolt holes 152. The holes 152 are provided forbolts 154 securing the starter motor assembly to the drive casing 20 and are paired symmetrically of a diametrical plane passing through one of the engine-mounting bolt holes 150. As best seen in Figures 2 and 4, the bolts 154 extend through the holes 152 and threadably engage four of a plurality of tapped holes 156 provided at 30 degree increments in the adapter member 18. This spacing of the tapped holes 156 provides twelve different positions of angularity for mounting the hydraulic starter motor relative to the drive casing 28-. Thus, the motor may be oriented to provide optimum locations for the control valve, the actuating handle, the pressure fittings, etc. for a given engine installation. The outlet fitting 72 may, of course, be mounted on either side of the valve plate in either of the outlet passages 66 or 68 depending on the engine-mounting requirements.

From the foregoing description, the operation of the hydraulic engine-starting device of the invention will be obviousto thoseskilled in the art. However, this operation. is detailed briefly below. a

The starter drive mechanism 6 including'the pinion gear 130 and the control valve spindle 96 are normally maintained in the positions shown in Figures 4 and 5 by theleVerbiasing spring 124. When it is desired to actuate the starting device, the actuating lever assembly is rotatedin a clockwise direction, as viewed in Figures land 4, simultaneously moving the valve spindle 96 and the starter drive'mechanism 6 to the right. As the valve spindle reaches=-itsintermediateopened position, the

pinion gear 130 will normally have been carried into engagement with the. engine fiywhel ring gear 132.: As-

the pinion gear is further shifted to full-driving engage ment with the ring gear, the valve spindle is shifted to arcuate inlet, port 52 in. the valve plate. The supplied pressurized hydraulic fluid enters the cylinder bores 48 through the mating ports 50-forcing the pistons 56 against the. camrace 58 which causes the rotation of the cylinder block 34 and of the shaft 14 thereby driving the pinion gear 130. As each piston 56 completes its outward stroke, the corresponding port 50 is brought into communication with the output port 54., As the cylinder barrel is further rotated,.the cam race 58 urges the piston inwardly of its bore thereby displacing the fluid in the cylinder bore through the outlet port 54.

When the engine has been started, the frictional drag of the hydraulic motor causes the .overrunning clutch to overrun thereby unloading the motor and preventing the engine. from driving the hydraulic motor. The dimension of the valve plate inlet passage 82 and the flow characteristics of the control valve are such as to restrict the flowof pressurized. fluid to the unloaded motor which would otherwise overspeed and rapidly bleed thepressuresource. Such overspeeding would also result in race. spring 124 returnsthe control valve and the starter drive mechanism to the leftto their valve-closed and piniondisengaged positions, respectively. It is contemplated that the actuating lever assembly could also include means responsiveto the starting of the engine to permit the return of the control valve and the drive mechanisms to those positions irrespective of the engine-start initiating control.

As shown in Figure 4a, the mating ends of'the pinion 139 of the starter drive mechanism' 6' and ring gear teeth 56am preferably; side chamfered to insure engagement when the starter drive mechanism is shifted. To further insure gear engagement prior to energization of the starter motor, the mating splines 131 and 133 of the pinion gear and clutch output sleeve, respectively, are preferably formed on a slight helix. However, these splines may be straight and are thus shown in Figure 4.

When end abutment of the gear teeth prevents engagement of the pinion and ring gear, limited further actuating movement of the actuating lever assembly is permitted by the compression of the pinion biasing spring 136 until abutment occurs between the ends of the spring guide portions of the member 137 and the pinion gear 130. Where the splines 131 and 133 are helical in form, the relative movement of the pinion and the sleeve compressing the spring Will efi'ect a limited rotation of the pinion tending to bring the gears into meshing alignment before the spring guide portions abut. when abutment of the spring guide'portions occurs, the

valve-spindle and the clutch mechanism will be restrained.

from further actuating movement until the gears are brought into meshing alignment and engagement occurs. This rest-rained position of the control valve corresponds to its hereinbefore described intermediate position wherein.

pressurized fluid is metered to the motor to produce a relatively slow rotation of the motor and the shaft 26 in. an engine driving direction until the teeth of the pinion.

and the ring gear are aligned for engagement, at which time the spring 136 will urge the pinion into mesh with the ring gear. When such engagement occurs, further shifting of the pinion and of the control valve to their.

However,

drive mechanism shown in Figure 4a, the pinion gear shifted force applied to the control lever assembly is augmented after initial gear engagement by the axial component of the torque reaction occurring between the mating helical splines as a result of the limited fluid supply effected engine driving rotation of the motor shaft 26, thus insuring actuation of the pinion gear into further full engagement with the ring gear.

While only one specific embodiment of the invention has been shown and described for the purposes of illustration, it will be appreciated that various modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

We claim:

1. A starting device for an engine comprising, in combinat-ion, a housing having a first chamber adapted to house a hydraulic motor and a second chamber adapted to house a starter drive mechanism; a shaft rotatably supported by said housing and having one end extending into said first chamber, a cylinder barrel slidably mounted on the end of said shaft within said first chamber, said cylinder barrel being restrained from rotation relative to its mounting on said shaft, bearing means carried by said housing adjacent each end of said cylinder barrel and rotatably journalling said cylinder barrel, said bearing means restraining said cylinder barrel from angular movement relative to its mounting on said shaft and to said housing, a plurality of bores extending longitudinally of the cylinder barrel, each of said bores having an axis spaced from and parallel to the axis of said shaft, a piston reciprocably supported in each of said cylinder bores and extending outwardly therefrom, the ends of said pistons extending outwardly of said bores being adapted to engage a thrust member rotatably mounted by said housing about an axis of rotation angularly disposed to and intersecting the axis of rotation of the cylinder barrel, 9. portion of said housing intermediate said chambers and remote from said rotatable thrust member having fluid passages through which hydraulic fluid is adapted to be sequentially delivered to the bores in said cylinder barrel and having fluid passages through which hydraulic fluid is adapted to be sequentially discharged from the bores in said cylinder barrel, means balancing the fluid pressures acting on said cylinder barrel and tending to shift said barrel axially of said chamber, and means biasing said cylinder barrel axially of said chamber into sealing engagement with said intermediate housing portion, the biasing action of said last-mentioned means being limited to that required for effecting a sealing engagement between said cylinder and said intermediate housing portion permitting limited leakage for the maintenance of a lubrieating film therebetween; starter drive mechanism including a pinion gear slidably mounted on said shaft within said second chamber and adapted to rotate therewith, said pinion gear being adapted to engage an enginedriven ring gear normally axially spaced from said pinion gear upon sliding movement of said starter drive mechanism on said shaft; valve means including an inlet chamber adapted to communicate with a source of high pres-. sure fluid, an outlet chamber adapted to communicate with a hydraulic fluid delivery passage in said intermediate housing portion, and a valve member having passage means therein for interconnecting said chamber, said valve member being adapted upon movement into one extreme position to interconnect said inlet and outlet chambers, upon movement into an intermediate position to permit the metering of hydraulic fluid from said inlet to said outlet chamber, and upon movement into another extreme position to prevent the flow of fluid therebetween;

and lever means for simultaneously shifting said valve' member and for sliding said pinion gear into engagement with said ring gear, and means associated with said starter drive mechanism for preventingmovement of said valve member by said lever means beyond said intermediate position until said pinion gear engages said drived gear.

2. A hydraulic engine-starting device comprising a housing having a first chamber adapted to house a hydraulic motor and a second chamber adapted to house a starter drive mechanism, a drive shaft rotatably supported by said housing and having one end extending into said first chamber, a starter drive mechanism including a pinion gear slidably mounted on said shaft within said second chamber and adapted to be rotatively driven therewith, said pinion gear being adapted to engage an engine ring gear normally axially spaced from said pinion gear upon sliding movement of said starter drive mechanism on said shaft, a cylinder barrel slidably mounted on the end of said shaft within said first chamber, said cylinder barrel being restrained from rotation and angular movement relative to its mounting on said shaft, spaced bearing means carried by said housing adjacent each end of said cylinder barrel and rotatably journalling said cylinder barrel within said first chamber, a plurality of bores extending longitudinally of the cylinder barrel, each of said bores having an axis spaced from and parallel to the axis of said shaft, a piston reciprocably supported in each of said cylinder bores and extending outwardly therefrom, each of said pistons having an arcuate head formed at a radius substantially equal to the piston diameter about a center located on the axis of said piston, a thrust member engaged by the arcuate heads of said pistons and rotatably mounted by said housing'about an axis of rotation angularly disposed to and intersecting the axis of rotation of the cylinder barrel at a point in a plane containing the centers of curvatures of the piston heads, a portion of said housing intermediate said chambers and remote from said rotatable thrust member having fluid passages therein through which hydraulic fluid is adapted to be sequentially delivered to and discharged from the bores in said cylinder barrel, means biasing said cylinder barrel axially of said shaft into rotative' sealing engagement with said intermediatehousing portion, valve means including an inlet chamber adapted to communicate with a source of high pressure fluid, an outlet chamber adapted to com municate with a hydraulic fluid delivery passage in said intermediate housing portion, and a valve member having passage means therein for interconnecting said inlet and outlet chambers, said valve member being adapted in one. extreme'position to prevent the flow of fluid between said inlet and outlet chambers, upon movement into an intermediate position to permit the metering of hydraulic fluid from said inlet to said outlet chamber, and upon movement into an opposite extreme position to interconnect said inlet and outlet chambers, and lever means for simultaneously shifting said valve member and for sliding said pinion gear into engagement with said driven gear, and means associated with said starter drive mechanism and said lever means for preventing movement of said valve member beyond said intermediate position until said pinion gear engages said driven gear. t

3. A hydraulic engine-starting device comprising a hensing having a first chamber adapted to house a hydraulic motor and a second chamber adapted to house a starter drive mechanism; a shaft rotatably supported by said housing and having one end extending into said first chamber; a hydraulic motor mounted within said first chamber and including a cylinder barrel slidably mounted on the end of said shaft within said first chamber, a plurality of bores extending longitudinally of said cylinder barrel, a portion of said housing intermediate said chambers having fluid passages through which hydraulic fluid is adapted to be sequentially delivered to and discharged from the bores in said cylinder barrel, means biasing said cylinder barrel axially of said shaft into fluid sealing engagement with saidintermediate housing portion, piston means reciprocably supported in said cylinder bores and extend ing outwardly therefrom, the outwardly extending end of each of said pistons being in thrust engagement with a' v ll cam member rotatably mounted in said housing remote from saidintermediate housing, portion about an axisof rotation angularly disposed to, andintersectingthe axis of rotation of the cylinder barrel, the cooperative action ofsaid'cam member and the fluid pressure delivered to said'bores being operable on said pistons to effect the rotation of said cylinder barrel, and means restraining said cylinder barrel'from movement relative to its mounting on said shafit exceptlongitudinally thereof, said means including bearing means carried "by said housing adjacent eachend of said cylinder barrel and rotatably journalling said cylinder barrel in said firstchamber; starter drive mechanism including a pinion gear slidably mounted on said shaft within said'secondchamber and adapted to rotate therewith, said pinion gear being adapted to engage an engine-driven gear axially spaced from said pinion gear upon sliding movement of said starter drive mechanism on said shaft; valvermeans mounted on said housingand including an inlet chamber adapted to communicate with a source of high pressure fluid, an outlet chamber adapted to communicate with one of said housing passages, and a valve member having passage means thereinfor interconnecting said chamber, said valve member being adapted upon movement into one position to interconnect said inlet and outlet chambers and upon movement into another position to prevent the flow of fluid therebetween; and a lever pivotally mounted on said housing and having a first arm for shifting said pinion gear in a direction to eifect engagement with said driven gear and having a second arm for simultaneously shifting said valve member towards said first-mentioned position, said valve member, said starter drive mechanism, and said lever means being so constructed and arranged that movement of said valve member to said first position is prevented until said pinion gear engages said driven gear.

4. A hydraulic engine-starting device comprising a housing including an end cap, a tubular housing member, an intermediate plate member, a motor-adapter member, and an engine-mounting member, saidend cap, said tubular member, said valve plate defining a first chamber adapted to house a hydraulic motor, said'valve plate, said adapter member and said engine-mounting member defining a second chamber adapted to house a starter drive mechanism; a shaft rotatably supported by said housing and having one end extending into said first chamber; a starter drive mechanism including a pinion gear slidably mounted on said shaft within said second cham ber and adapted to rotate therewith, said pinion gear being adapted to engage an engine-driven gear axially spaced from'sa-idpinion gear upon shifting of said starter drive mechanism axially of said shaft; a hydraulic motor mountedin said first chamber including a cylinder barrel s'li'dably mounted on the end of said shaft within said first chamber, a plurality of bores extending longitudinally of said, cylinder barrel, said bores having axes spaced from and parallel to the axis of said shaft, the intermediate plate member of said housing having fluid'passages through which hydraulic fluid is adapted to be se- 12. v of said cylinder barrel and rotatably journalling said cylinder, barrel in said first chamber; valve means mounted 'onrsaid, intermediatemember including an inlet chamber adapted to communicate with a source of high pressure fluid, an outlet chamber adapted to communicate with one of said housing passages, and a valve member having passage means therein for interconnecting said valve chambers, said valve member, being adaptedupon movement into one position to interconnect said inlet quentially deliveredto and discharged from the bores in said cylinder barrel, means biasing said cylinder barrel axially of said shaft into fluid sealing engagement with said intermediate housing portion, a piston reciprocably mounted in each of said cylinder bores and extending outwardly therefrom, the outwardly extending end of each of said pistons being in thrust engagement with a cam member rotatably mounted in said end cap and the adjacent end of said housing member about an axis of rotation angularly disposed to and intersecting the axis of rotation of the cylinder barrel, the cooperative action of said cannmeinber and the fluid pressure delivered to said bores bcingopcrable on saidpistons to efiect the rotation oisaid cylinder-barrel, means restraining saidcylinder harreltrom movement relative to its mountingon said bearing means carried by said housing adjacent each end and outlet chambers and into another position to prevent the how of fluid therebetween; and lever means pivotally mountedon saidadapter member and having a first arm for shifting said pinion gear into engagement with said drivengear and a second arm for simultaneously shifting said valve member towards said first-mentioned position, said valve member, said starter drive mechanism and said lever means being so constructed and arranged that movement of said valve member to said first position is prevented until said pinion gear engages said driven gear; said housing elements having means associated therewith for changing the angular disposition thereof with respect to each other about the drive shaft.

5. A hydraulic engine-starting device comprising a housing having a first chamber housing a hydraulic motor and a second chamber housing a starter drive mechanism, a drive shaft rotatably supported by said housing and having one end extending into said first chamber, said starter drive mechanism including a pinion gear slidably mounted on said shaft within said second chamber and adapted to be rotatively driven therewith, said pinion gear being adapted to engage an engine ring gear normally axially spaced from said pinion gear upon sliding movement of said starter drive mechanism on said shaft, said hydraulic motor drivingly connected to the end of said shaft within said first chamber, said housing having fluid passages therein through which hydraulic fluid is delivered to and discharged from said motor, valve means including an inlet chamber adapted to communicate with a source of high pressure fluid, an outlet chamber communicating with a hydraulic fluid delivery passage in said housing, and a valve member having passage means therein for interconnecting said inlet and outlet chambers, said valve member being adapted in one extreme position to prevent the flow of fluid between said inlet and outlet chambers, said passage means including flow restricting orifice means adapted upon movement of said valve member through an intermediate position to meter a restricted flow of hydraulic fluid from said inlet to said outlet chamber, said passage means being operable upon movement of said valve member into an opposite extreme position to interconnect and provide relatively unrestricted fluid flow between said inlet and outlet chambers, lever means for simultaneously shifting said valve member and said pinion gear, said lever means being adapted to carry said valve member to said intermediate position normally upon initial engagement of said gears and to said opposite extreme position with movement of said pinion gear into substantially full engagement with said driven gear, yieldable means associated with said starter, drive mechanism and operable to permit movement of said valve member by said lever means to its intermediate restricted flow supplying position upon gear tooth end abutment between said pinion and driven gears, and means associated with said starter drive mechanism for preventing movement of said valve member by said lever means beyond said intermediate restricted flow position toward said opposite extreme position until said pinion gear is insubstantially full engagement with said driven gear.

6. A hydraulic engine-starting device comprising a housing having a first chamber housing a hydraulic motor and a second chamber housing a starter drive mechanism; a shaft rotatably supported by said housing and having one end extending into said first chamber; said hydraulic motor mounted withinvsaid first chamber andconnected to rotatably drive the end of said shaft extending within said first chamber, said housing having fluid passages therein through which hydraulic fluid is adapted to be delivered to and discharged from said motor; said starter drive mechanism including a pinion gear slidably mounted on said shaft within said second chamber and adapted to rotate therewith, said pinion gear being adapted to engage an engine-driven gear axially spaced from said pinion gear upon sliding movement of said starter drive mechanism; valve means including an inlet chamber adapted to communicate with a source of high pressure fluid, an outlet chamber in communication with one of said housing passages, and a valve member having passage means therein for interconnecting said valve chambers, said valve member being adapted upon movement into one position to interconnect said inlet and outlet chambers and upon movement into another position to prevent the flow of fluid therebetween; and a lever pivotally mounted on said housing and having a first arm for shifting said pinion gear in a direction to effect engagement with said driven gear and having a second arm for simultaneously shifting said valve member toward said first-mentioned position; said valve member, said starter drive mechanism, and said lever means being so constructed and arranged that movement of said valve member to said first-mentioned position is prevented until said pinion gear is in substantially full engagement with said driven gear.

7. A hydraulic engine-starting device comprising a drive shaft mounted for rotation, a starter drive mechanism including a pinion slidably mounted on said shaft and adapted to be rotatively driven therewith, said pinion being adapted upon sliding movement of said starter drive mechanism on said shaft to engage an engine ring gear normally axially spaced from said pinion, a hydraulic motor drivingly connected to said shaft, passage means associated with said motor and including a delivery passage and a discharge passage through which hydraulic fluid is delivered to and discharged from said motor, valve means operable to connect said fluid delivery passage with a source of high pressure fluid, said valve means including a shiftable valve member adapted in a first extreme position to prevent the flow of fluid between said source and said delivery passage, upon movement into an intermediate position to permit the metering of hydraulic fluid from said source to said delivery passage, and upon movement into a second extreme position to interconnect and to provide relatively unrestricted fluid flow between said source and said delivery passage, lever means for simultaneously shifting said valve member and said pinion gear, said lever means being adapted to carry said valve member to its intermediate position normally upon initial engagement of said gears and to its opposite extreme position with movement of said pinion gear into substantially full engagement with said driven gear, and means associated with said starter drive mechanism and said lever means for preventing movement of said valve member beyond its intermediate position toward its second extreme position until said pinion gear is in substantially full engagement with said driven gear.

8. A hydraulic motor comprising a housing having a chambertherein, a shaft rotatably supported by said housing and extending into said chamber, a cylinder barrel slidably mounted on said shaft Within said chamber, said cylinder barrel being restrained from rotation and angular movement relative to its mounting on said shaft, a plurality of bores extending longitudinally of the cylinder barrel, a piston reciprocably supported in each of said cylinder bores, the ends of said pistons extending outwardly from said bores and engaging a cam member rotatably mounted by said housing about an axis of rotation angularly disposed to and intersecting the axis of rotation of the cylinder barrel, the end of said housing adjacent the end of said cylinder barrel remote from said rotatable cam member having fluid passages through which hydraulic fluid is adapted to be sequentially delivered to and discharged from the bores in said cylinder barrel, bearing means spaced axially of said cylinder barrel and rotatably journalling said cylinder barrel adjacent each end thereof within said chamber, said bearing means restraining said cylinder barrel from lateral and angular displacement relative to said housing end portion, and means biasing said cylinder barrel axially of said shaft into rotative thrust engagement with said housing end portion, said thrust engagement permitting the maintenance of a lubricating film between said housing end and said cylinder barrel and effectively sealing said bores and said passages under all motor operative conditions.

9. A hydraulic motor comprising, in combination, a housing having a chamber therein, a cylinder barrel rotatable about an axis within said chamber, a plurality of bores in said cylinder barrel having axes spaced from and parallel to said axis of rotation, a piston member reciprocably supported in each of said cylinder bores, the ends of said pistons extending outwardly of said bores and engaging a thrust member rotatably supported by said housing about an axis of rotation inclined to intersect the axis of rotation of said cylinder barrel, the end of said housing remote from said rotatable thrust member having passages therein through which hydraulic fluid is adapted to be sequentially delivered to and discharged from the bores in said cylinder barrel, means substantially balancing the fluid pressures acting on said cylinder barrel and otherwise tending to shift said barrel axially of said chamber, antifriction bearing means spaced axially of and journalling said cylinder barrel adjacent the axial ends thereof within said housing chamber, and resilient means biasing said cylinder barrel axially of said chamber into sealing engagement with said remote end of said housing, the biasing action of said resilient means being limited to that required for eflecting a sealing engagement between said cylinder and housing ends permitting limited leakage for the maintenance of a lubricating film therebetween, said bearing means restraining said cylinder barrel from lateral and angular displacement relative to said housing end portion.

10. In a hydraulic motor including a housing having a chamber therein, a cylinder barrel rotatable about an axis within said chamber and having a plurality of bores in said cylinder barrel having axes spaced from and parallel to said axis of rotation, a piston member reciprocably supported in each of said cylinder bores, the ends of said pistons extending outwardly of said bores and engaging a thrust member rotatably supported by said housing, the axis of rotation of said thrust member being inclined to intersect the axis of rotation of said cylinder barrel, the end of said housing remote from said rotatable thrsut member having fluid passages therein through which hydraulic fluid is adapted to be sequentially delivered to and discharged from the bores in said cylinder barrel, bearing means carried by said housing in axially spaced relation and journalling said cylinder barrel adjacent each axial end thereof within said housing chamber, said bearing means restraining said cylinder barrel from angular or lateral displacement relative to said axis, and means biasing said cylinder barrel axially of said chamber into rotative thrust engagement with said remote end of said housing, said thrust engagement being limited to permit the maintenance of a lubricating film eflectively sealing said cylinder and housing 15 12. A hydraulic engine claim 7, including means associated with said starter drive mechanism for rotating said pinion relative to said shaft upon movement of said drive mechanism toward said engine ring gear upon gear tooth end abutment between said pinion and engine ring gear, said last mentioned means being further responsive to rotation of said shaft in an engine driving direction to urge said pinion into engagement with said ring gear.

13. A hydraulic engine starting device as set forth in claim 7, including yieldable means associated with said starter drive mechanism and operable to permit movement of said valve member by said lever means to its intermediate restricted flow supplying position upon gear tooth end abutment between said pinion and said engine ring gear, and means associated with said starter drive mechanism for rotating said pinion relative to said shaft upon movement of said valve member to its intermediate restricted flow position as permitted by said yieldable means upon gear tooth end abutment.

14. A hydraulic engine starting device as, set forth in claim 13 wherein said last-mentioned means is respon-- sive to engine driving rotation of said shaft by said motor starting device as set forth in.

to urge, said: pinion into further engagement with said' e n ling gear- 15; A hydraulic engine starting device as set forth in claim 6, including yieldable meansoperable to-permit limited valve shifting movement of said lever means upon gear. tooth end abutment between said pinion and engine ring gears, and means associated with said starter References Cited in the file of this patent UNITED STATES PATENTS 2,417,816 Fallon Mar. 25, 1947 2,565,582 White Aug. 28, 1951 2,710,606 Jenny June 14, 1955 2,847,984 Gallant Aug. 19, 1958 2,862,391 Schneider et a1. Dec. 2, 1958 

